ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCC%28O%29OC%28CC%29O.CC%28COCC%28C%29O%29O/file?format=sdf&get3d=True  -- CCC%28O%29OC%28CC%29O.CC%28COCC%28C%29O%29O could not be loaded.